Is there a way of fetching the date/time or size of a file on the Internet?
in [Visual Basic]
|
Prev: Printing the Form
Next: Common Controls 5.0 / Windows 7
From: Tony Toews [MVP] on 8 Nov 2009 19:36 "Nobody" <nobody(a)nobody.com> wrote: >Besides what mayayana suggested, check this sample: > >SAMPLE: Vbhttp.exe Demonstrates How to Use HTTP WinInet APIs in Visual Basic >http://support.microsoft.com/kb/259100/en-us > >I just tried it. It doesn't have "HEAD" option in the GUI, so in >btSend_Click(). I changed "GET" to "HEAD", specified the URL to a ZIP >file(without http://) and it worked fine, without downloading the whole >file. Server logs shows that only 273 bytes were transferred as opposed to >2MB. Ah, thanks kindly. I was hoping that the download would be significantly less than 273 bytes but that's the way it goes. And the file I'm looking at downloading might not be too much larger than 273 bytes. Trouble is there could be thousands of them so I was hoping to reduce the load on the server. Tony -- Tony Toews, Microsoft Access MVP Tony's Main MS Access pages - http://www.granite.ab.ca/accsmstr.htm Tony's Microsoft Access Blog - http://msmvps.com/blogs/access/ For a free, convenient utility to keep your users FEs and other files updated see http://www.autofeupdater.com/ Granite Fleet Manager http://www.granitefleet.com/
From: Tony Toews [MVP] on 8 Nov 2009 20:16 "mayayana" <mayaXXyana(a)rcXXn.com> wrote: > The following link is for a userControl that uses >winsock directly. I've been thinking about this and I feel I'd be much better off going directly against the Winsock rather than depending on IE stuff. Whatever MSs definition of stuff is. <smile> Thanks for posting that link. Tony -- Tony Toews, Microsoft Access MVP Tony's Main MS Access pages - http://www.granite.ab.ca/accsmstr.htm Tony's Microsoft Access Blog - http://msmvps.com/blogs/access/ For a free, convenient utility to keep your users FEs and other files updated see http://www.autofeupdater.com/ Granite Fleet Manager http://www.granitefleet.com/
From: Nobody on 8 Nov 2009 20:32 "Tony Toews [MVP]" <ttoews(a)telusplanet.net> wrote in message news:rsoef518d290jlm0iuasvlejdnmkk09s48(a)4ax.com... > "Nobody" <nobody(a)nobody.com> wrote: > >>Besides what mayayana suggested, check this sample: >> >>SAMPLE: Vbhttp.exe Demonstrates How to Use HTTP WinInet APIs in Visual >>Basic >>http://support.microsoft.com/kb/259100/en-us >> >>I just tried it. It doesn't have "HEAD" option in the GUI, so in >>btSend_Click(). I changed "GET" to "HEAD", specified the URL to a ZIP >>file(without http://) and it worked fine, without downloading the whole >>file. Server logs shows that only 273 bytes were transferred as opposed to >>2MB. > > Ah, thanks kindly. I was hoping that the download would be > significantly less than 273 bytes but that's the way it goes. And > the file I'm looking at downloading might not be too much larger than > 273 bytes. Trouble is there could be thousands of them so I was > hoping to reduce the load on the server. The 273 bytes are the HTTP header length. FTP maybe smaller. Here is an example header that I just tried, it's 250 bytes long when I pasted it into a hex editor. Server logs also show that 250 bytes were transferred. I used HEAD method. Actual file length is 7103 bytes as shown in Content-Length. HTTP/1.1 200 OK Content-Length: 7103 Content-Type: text/html Last-Modified: Mon, 26 Oct 2009 22:56:44 GMT Accept-Ranges: bytes ETag: "0de92968f56ca1:470e" Server: Microsoft-IIS/6.0 X-Powered-By: ASP.NET Date: Mon, 09 Nov 2009 01:25:11 GMT
From: Nobody on 8 Nov 2009 20:48 "Tony Toews [MVP]" <ttoews(a)telusplanet.net> wrote in message news:uooef593eiok0a809kth8kikqj2q7qb23m(a)4ax.com... > Ah, now that's interesting. I wonder what happens if IE doesn't exist > on the system. Aren't the EU versions of Windows setup so that IE is > optional? Or something like that. You can count on WinInet API being present, even if IE itself wasn't present. For the EU, there is N version and proposed E version that was later cancelled. N stands for Not with Media Player, while E stands for IE. In the E version, only iexplore.exe would be removed, which doesn't effect WinInet API. http://en.wikipedia.org/wiki/Windows_XP_N#Windows_XP_Edition_N See also: http://en.wikipedia.org/wiki/Internet_Explorer#Removal The only thing you can't count on is using WinInet API from a service. See this article for details: INFO: WinInet Not Supported for Use in Services http://support.microsoft.com/kb/238425/en-us
From: mayayana on 8 Nov 2009 22:08
An additional note for completeness: Some servers use gzip compression, which a browser will normally deal with. But when the request is made directly one's own software has to deal with it. It seems that if one does not send an Accept-Encoding: line in the request then it will not be zipped, but it's a good idea to check for a Content-Encoding: line in the header, anyway. If it's there then hopefully it's gzipped -- Content-Encoding: gzip In that case it can be easily unzipped using the zlib library. Nobody <nobody(a)nobody.com> wrote in message news:#FWQ6xNYKHA.4688(a)TK2MSFTNGP06.phx.gbl... > "Tony Toews [MVP]" <ttoews(a)telusplanet.net> wrote in message > news:rsoef518d290jlm0iuasvlejdnmkk09s48(a)4ax.com... > > "Nobody" <nobody(a)nobody.com> wrote: > > > >>Besides what mayayana suggested, check this sample: > >> > >>SAMPLE: Vbhttp.exe Demonstrates How to Use HTTP WinInet APIs in Visual > >>Basic > >>http://support.microsoft.com/kb/259100/en-us > >> > >>I just tried it. It doesn't have "HEAD" option in the GUI, so in > >>btSend_Click(). I changed "GET" to "HEAD", specified the URL to a ZIP > >>file(without http://) and it worked fine, without downloading the whole > >>file. Server logs shows that only 273 bytes were transferred as opposed to > >>2MB. > > > > Ah, thanks kindly. I was hoping that the download would be > > significantly less than 273 bytes but that's the way it goes. And > > the file I'm looking at downloading might not be too much larger than > > 273 bytes. Trouble is there could be thousands of them so I was > > hoping to reduce the load on the server. > > The 273 bytes are the HTTP header length. FTP maybe smaller. Here is an > example header that I just tried, it's 250 bytes long when I pasted it into > a hex editor. Server logs also show that 250 bytes were transferred. I used > HEAD method. Actual file length is 7103 bytes as shown in Content-Length. > > HTTP/1.1 200 OK > Content-Length: 7103 > Content-Type: text/html > Last-Modified: Mon, 26 Oct 2009 22:56:44 GMT > Accept-Ranges: bytes > ETag: "0de92968f56ca1:470e" > Server: Microsoft-IIS/6.0 > X-Powered-By: ASP.NET > Date: Mon, 09 Nov 2009 01:25:11 GMT > > |